The Boston Celtics could still be looking to acquire another free agent or two.

Sam Amick of Sports Illustrated reported Wednesday that the Celtics are interested in free agents Kenyon Martin and Terrence Williams.

Boston already has the maximum 15 players under contract, not including Jamar Smith, a guard who is expected to compete for a roster spot in training camp. That means they'll have to drop someone if they do sign Martin or Williams.

Martin had one of the least productive seasons in his NBA career last year for the Los Angeles Clippers, averaging 5.2 points and 4.3 rebounds per game. He notched a career low 8.3 points per 36 minutes and his rebounding rate (11.5) was the third-lowest of his career, though it still tied him with Celtics starter Brandon Bass. If the 2006-07 season isn't counted because Martin managed just two games played, his PER last season (9.9) was the lowest of his career. Still, the Clippers were 6.35 points per 100 possessions better with Martin on the floor and their defense performed at a considerably higher level with him, too (7.16 points better per 100 possessions).

Williams has struggled to emerge as a role player in the NBA after wowing with potential and production at Louisville, averaging 7.6 points and 3.9 rebounds over three NBA seasons. Though athletic and skilled, Williams has yet to find a niche where he can thrive in the NBA. Still just 25, his potential remains intriguing although he's running out of time to show he can ever reach it.